rear wiring harness

[bikernut]

I purchased an 2003 GMC 3500 standard cab 4x4 with a dump body. I have been having electrical problem from the start in the rear over the dual fuel tanks. When they did the dump body they hacked into the rear harness on the frame and I do mean hacked as it didn't come with a trailer wiring outlet so they made one and hooked up the body lights ( stop, tail, directional, and backup) they removed the tail light that came with the cab & chassis and added there own that came with the body. to cut to the chase here what I would like to do is replace the harness that runs down the left side frame with one that has the trailer harness incorporated into it and goes to the junction panel on the rear cross member and the I can make the correct splicing with soldier joints not those damn splice connectors and doing this on the trailer wiring harness I had on my other 05 pickup to go to my bed up by the cab for a fifth wheel that plugs into the factory harness at the rear bumper. does any bode know where it connects on the from of the truck and runs the length of the frame to the rear, and what about the part # for this as my truck at the dealership doesn't show a parts as my truck didn't come with a trailer hauling package? does any one have a wiring schematic for a 2003 GMC/Chevy 3500 cab and chassis with dual fuel tanks that I can understand?
thanks for any help

[izzy_Britton]

Originally Posted by bikernut

I purchased an 2003 GMC 3500 standard cab 4x4 with a dump body. I have been having electrical problem from the start in the rear over the dual fuel tanks. When they did the dump body they hacked into the rear harness on the frame and I do mean hacked as it didn't come with a trailer wiring outlet so they made one and hooked up the body lights ( stop, tail, directional, and backup) they removed the tail light that came with the cab & chassis and added there own that came with the body. to cut to the chase here what I would like to do is replace the harness that runs down the left side frame with one that has the trailer harness incorporated into it and goes to the junction panel on the rear cross member and the I can make the correct splicing with soldier joints not those damn splice connectors and doing this on the trailer wiring harness I had on my other 05 pickup to go to my bed up by the cab for a fifth wheel that plugs into the factory harness at the rear bumper. does any bode know where it connects on the from of the truck and runs the length of the frame to the rear, and what about the part # for this as my truck at the dealership doesn't show a parts as my truck didn't come with a trailer hauling package? does any one have a wiring schematic for a 2003 GMC/Chevy 3500 cab and chassis with dual fuel tanks that I can understand?
thanks for any help

I DO NOT have a part number for you but i do have a hacked wire harness... my harness is hacked from just under the front edge of the cab forward. I can look this weekend to see what is there and maybe it will help?

I bought an 04 2500HD a few months back and cut the frame under the cab to make a pickup bed trailer out of the rest of it.

-Izzy

[izzy_Britton]

my truck was only a single tank but i am sure that is not the hardest part to figure out?

[bikernut]

thanks but I need one that isn't cut up so I can stop having rear light issues and such with all the splicing. again thanks for the offer

[izzy_Britton]

i misspoke...

it would appear that i have not gotten around to cutting the harness up yet.



there are 3 wires in their own loom that i believe to be trailer lights for this truck, but they were added by PO. the rest of the harness looks complete from underhood fuse panel to the rear. to be honest i have not looked under the back to see how it is but i assume it is ok.

of coarse i still need to drop fuel tank to get to those plugs/connections.

how can i help?

-Izzy

[bikernut]

thanks, I would like the whole thing if you could give me a week or so as I think I have a lead on another one but it is still in the talking stage so I don't know if it is promising or not.
If not what is your asking price for that whole harness? You also said the trailer package was 3 wires that was installed by PO what or who is PO?
thanks
Pete

[izzy_Britton]

PO = previous owner

[bikernut]

thanks
Did you work out a price on yours if the other guy doesn't have the one he thinks?
thanks

[bikernut]

guy just emailed me and says that the one he has will not work, truck is to old not compatible so I guess I am waiting what you come up with for a price on yours.
thanks
Pete

[izzy_Britton]

You have PM

[franken]

Not sure if it'll help...

https://www.google.com/search?q=wiri...evy+truck+rear
https://www.google.com/search?q=wiri...rear+schematic

[izzy_Britton]

Pete You have PM again!

[bikernut]

thanks Franken